Electronic Devices Having Electrically Adjustable Optical Shutters

ABSTRACT

An electronic device has an electrically adjustable shutter. The shutter may be placed in a transparent state or a nontransparent state. The shutter may overlap a portion of a display, may overlap a liquid contact indictor or a structure with text in a device, or may overlap an optical component such as an optical proximity sensor, ambient light sensor, visible light-emitting diode or laser, infrared light-emitting diode or laser, visible light image sensor, or infrared light image sensor. Control circuitry in the electronic device may place the shutter in an opaque state to hide an overlapped component from view or may place the shutter in a transparent state to allow the overlapped component to transmit or receive light. The adjustable shutter may exhibit changes in its transmission spectrum in different modes of operation and may be used as a camera filter or neutral density filter.

This application is a continuation of U.S. patent application Ser. No.16/808,911, filed Mar. 4, 2020, which is a continuation of U.S. patentapplication Ser. No. 15/887,661, filed Feb. 2, 2018, now U.S. Pat. No.10,690,986, which claims the benefit of provisional patent applicationNo. 62/558,110, filed Sep. 13, 2017, which are hereby incorporated byreference herein in their entireties.

FIELD

This relates generally to electronic devices, and, more particularly, toelectronic devices with electrically adjustable optical shutters.

BACKGROUND

Electronic devices such as laptop computers, cellular telephones, andother equipment are sometimes provided with optical components. Theoptical components may include components such as an image sensor(camera), a camera flash, an optical proximity sensor, or an ambientlight sensor. Components such as these generally operate through windowsin device housings or portions of a display. Although optical coatingstructures can sometimes be provided on windows to help blend theirvisual appearance with surrounding structures, it is often difficult orimpossible to effectively hide an optical component behind a window. Asa result, conventional electronic devices often have windows that arenot as visually appealing ad desired.

SUMMARY

An electronic device may be provided with optical components and othercomponents. The optical components may include an optical proximitysensor, ambient light sensor, visible light-emitting diode, visiblelaser, infrared light-emitting diode, infrared laser, visible lightimage sensor, or infrared light image sensor. An optical componentwindow may be aligned with one or more optical component windows.

An electrically adjustable shutter may be provided. The shutter may bealigned with an optical component window or may be mounted in otherportions of an electronic device. In some configurations, the shuttermay overlap a portion of a display such as a transparent display. Inother configurations, the shutter may overlap a liquid contact indictor,an optical data port, or a region with text.

The shutter may be dynamically adjusted by control circuitry in thedevice to adjust the optical properties of the shutter. For example, theshutter may be placed in a transparent state or a state in which theshutter is not transparent. During operation, control circuitry in theelectronic device may place the shutter in an opaque state to hide anoverlapped component from view or may place the shutter in a transparentstate to allow the overlapped component to transmit or receive light.The adjustable shutter may exhibit changes in its transmission spectrumin different modes of operation and may be used as a spectral filter orneutral density filter for a camera or other optical component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an illustrative electronic device withan adjustable optical shutter in accordance with an embodiment.

FIG. 2 is a side view of an illustrative electronic device in accordancewith an embodiment.

FIG. 3 is a front perspective view of an illustrative electronic devicein accordance with an embodiment.

FIG. 4 is a rear perspective view of an illustrative electronic devicein accordance with an embodiment.

FIG. 5 is a side view of an illustrative adjustable optical shutteroverlapping a component to be hidden from view such as an opticalcomponent or other structure to be selectively hidden in accordance withan embodiment.

FIG. 6 is a side view of an illustrative electronic device with atransparent display and adjustable optical shutter in accordance with anembodiment.

FIG. 7 is a cross-sectional side view of an illustrative light sourceand associated reflector in accordance with an embodiment.

FIG. 8 is a cross-sectional side view of an illustrative light sourceand associated Fresnel lens in accordance with an embodiment.

FIG. 9 is a side view of an illustrative adjustable liquid crystalshutter in accordance with an embodiment.

FIG. 10 is a cross-sectional side view of an illustrative adjustableelectrowetting shutter in a closed configuration in accordance with anembodiment.

FIG. 11 is a cross-sectional side view of the adjustable electrowettingshutter of FIG. 10 in an open configuration in accordance with anembodiment.

FIG. 12 is a top view of the illustrative electrowetting shutter ofFIGS. 10 and 11 in accordance with an embodiment.

DETAILED DESCRIPTION

Electronic devices may be provided with electrically adjustable opticalshutters. The electrically adjustable shutters may be used to adjust theoutward appearance of one or more portions of an electronic device. Forexample, an electrically adjustable shutter may be overlap a componentor structure in the interior of an electronic device. The state of theelectrically adjustable shutter may be dynamically adjusted to allowlight to pass or to provide the adjustable shutter with an opaqueappearance or other desired appearance. In some configurations, theelectrically adjustable shutter may be placed in a dark state or othernon-transparent state to hide an overlapped optical component or otherdevice structure from view while visually blending the appearance of theadjustable shutter with surrounding device housing structures.

An illustrative electronic device of the type that may be provided withan electrically adjustable shutter is shown in FIG. 1. Electronic device10 may be a computing device such as a laptop computer, a computermonitor containing an embedded computer, a tablet computer, a cellulartelephone, a media player, or other handheld or portable electronicdevice, a smaller device such as a wrist-watch device, a pendant device,a headphone or earpiece device, a device embedded in eyeglasses or otherequipment worn on a user's head, or other wearable or miniature device,a television, a computer display that does not contain an embeddedcomputer, a gaming device, a navigation device, an embedded system suchas a system in which electronic equipment with a display is mounted in akiosk or automobile, equipment that implements the functionality of twoor more of these devices, or other electronic equipment.

As shown in FIG. 1, electronic device 10 may have control circuitry 16.Control circuitry 16 may include storage and processing circuitry forsupporting the operation of device 10. The storage and processingcircuitry may include storage such as hard disk drive storage,nonvolatile memory (e.g., flash memory or otherelectrically-programmable-read-only memory configured to form a solidstate drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Processing circuitry in control circuitry 16may be used to control the operation of device 10. The processingcircuitry may be based on one or more microprocessors, microcontrollers,digital signal processors, baseband processors, power management units,audio chips, application specific integrated circuits, etc.

Device 10 may have input-output circuitry such as input-output devices12. Input-output devices 12 may include user input devices that gatheruser input and output components that provide a user with output.Devices 12 may also include sensors that gather information from theenvironment. Communications circuitry 20 may be used to receive data fordevice 10 and may be used to supply data from device 10 to externaldevices. Communications circuitry 20 may include one or more antennas anassociated radio-frequency transceiver circuitry. The transceivercircuitry may include wireless local area network transceiver circuitry,cellular telephone transceiver circuitry, and/or other radio-frequencytransceiver circuitry and may operate in any suitable frequency band(e.g., a frequency of 700-2700 MHz, 2.4-5 GHz, less than 700 MHz, morethan 2700 GHz, etc.).

Input-output devices 12 may include one or more displays such as display14. Display 14 may be a touch screen display that includes a touchsensor for gathering touch input from a user or display 14 may beinsensitive to touch. A touch sensor for display 14 may be based on anarray of capacitive touch sensor electrodes, acoustic touch sensorstructures, resistive touch components, force-based touch sensorstructures, a light-based touch sensor, or other suitable touch sensorarrangements. Display 14 may be a liquid crystal display, alight-emitting diode display (e.g., an organic light-emitting diodedisplay), an electrophoretic display, or other display.

Input-output devices 12 may include optical components 18. Opticalcomponents 18 may include ambient light sensors (e.g., color ambientlight sensors configured to measure ambient light color and intensity bymaking light measurements with multiple light detector channels each ofwhich has a corresponding color filter and photodetector to measurelight in a different wavelength band), optical proximity sensors (e.g.,sensors with a light-emitting device such as an infrared light-emittingdiode and a corresponding light detector such as an infrared photodiodefor detecting when an external object that is illuminated by infraredlight from the light-emitting diode is in the vicinity of device 10), avisible light camera (visible light digital image sensor), an infraredlight camera (infrared digital image sensor), light-emitting diodesand/or laser diodes that emit flash illumination for visible lightcameras (sometimes referred to as camera flash), infrared light-emittingdiodes that emit illumination for infrared cameras, light-emittingdiodes and/or lasers and sensors that support optical communications inan optical data port, and/or other optical components.

In addition to optical components 18, input-output devices 12 mayinclude buttons, joysticks, scrolling wheels, touch pads, key pads,keyboards, microphones, speakers, tone generators, vibrators, cameras,lasers, light-emitting diodes and other status indicators, non-opticalsensors (e.g., temperature sensors, microphones, capacitive touchsensors, force sensors, gas sensors, pressure sensors, sensors thatmonitor device orientation and motion such as inertial measurement unitsformed from accelerometers, compasses, and/or gyroscopes), data ports,etc. A user can control the operation of device 10 by supplying commandsthrough input-output devices 12 and may receive status information andother output from device 10 using the output resources of input-outputdevices 12.

Device 10 may have one or more electrically adjustable shutters such aselectrically adjustable shutter 8. Shutter 8 may be adjusted to operatein different light transmission modes. For example, in different modesof operation, shutter 8 may exhibit different light transmission values(e.g., a high transmission value of at least 80% or at least 90% and alow transmission value of less than 40%, less than 20%, or less than10%), different colors (e.g., non-neutral colors such as blue, red,green, blue-black, etc.), different neutral colors (white, black, gray,etc.), different reflectivities (e.g., a low reflectivity of less than40%, less than 20%, or less than 10% or a high reflectively of more than60%, more than 80%, or more than 90%), different light absorption values(and/or different light absorption spectral shapes), different amountsof haze, and/or other properties that vary the appearance and/or lighttransmission, absorption, and/or reflection of shutter 8. Electricallyadjustable shutter 8 may be formed from a liquid crystal device, anelectrochromic device, a suspended particle device, an electrophoreticdevice, an electrowetting device, and/or other adjustable devices thatexhibit adjustable optical properties such as haze, light reflection,light absorption, and/or light transmission.

Device 10 may have a housing. The housing may form a laptop computerenclosure, an enclosure for a wristwatch, a cellular telephoneenclosure, a tablet computer enclosure, or other suitable deviceenclosure. A side view of an illustrative electronic device is shown inFIG. 2. The illustrative device of FIG. 2 has a planar configuration(e.g., for a portion of a laptop computer, a tablet computer, a cellulartelephone, etc.). This arrangement is presented as an example. Ingeneral, housing 22 of device 10 may have any suitable configuration.

In the example of FIG. 2, device 10 has opposing front and rear faces(front face F and rear face R). Display 14 may be mounted in housing 22on front face F of device 10. Portions of housing 22 (e.g., a planarrear housing wall) may be formed on rear face R of device 10. Housing22, which may sometimes be referred to as an enclosure or case, may beformed of plastic, glass, ceramics, fiber composites, metal (e.g.,stainless steel, aluminum, etc.), other suitable materials, or acombination of any two or more of these materials. Housing 22 may beformed using a unibody configuration in which some or all of housing 22is machined or molded as a single structure or may be formed usingmultiple structures (e.g., an internal frame structure, one or morestructures that form exterior housing surfaces, etc.).

Display 14 may be protected using a display cover layer such as a layerof transparent glass, clear plastic, sapphire, or other clear layer(e.g., a transparent planar member that forms some or all of a frontface of device 10 or that is mounted in other portions of device 10).Openings may be formed in the display cover layer. For example, anopening may be formed in the display cover layer to accommodate abutton, a speaker port, or other components. Openings may be formed inhousing 22 to form communications ports (e.g., an audio jack port, adigital data port, an optical port, etc.), to form openings for buttons,etc. In some configurations, housing 22 may have a rear housing wallformed from a planar glass member or other transparent layer (e.g., aplanar member formed on rear face R of device 10 opposing a displaycover layer formed on front face F of device 10). In someconfigurations, a transparent planar member forming the rear housingwall may have an interior surface that is coated with an opaque maskinglayer. Window structures (e.g., for cameras, camera flash, and otheroptical components) may be formed in display 14 (e.g., in a displaycover layer), in housing 22 (e.g., in a rear housing wall or a planar orcurved housing sidewall), and/or in other portions of device 10.

FIG. 3 is a front perspective view of the illustrative electronic deviceof FIG. 2. As shown in FIG. 3, display 14 may be mounted in housing 22on front face F of device 10. Display 14 may have an array of pixels 28in active area AA (e.g., liquid crystal display pixels, organiclight-emitting diode pixels, electrophoretic display pixels, etc.).Pixels 28 of active area AA may display images for a user of device 10.Active area AA may be rectangular or may have other suitable shapes.

Inactive portions of display 14 such as inactive border area IA may beformed along one or more edges of active area AA. Inactive border areaIA may overlap circuits, signal lines, and other structures that do notemit light for forming images. To hide inactive circuitry and othercomponents in border area IA from view by a user of device 10, theunderside of the outermost layer of display 14 (e.g., the display coverlayer or other display layer) may be coated with an opaque maskingmaterial such as a layer of black ink (e.g., polymer containing blackdye and/or black pigment, opaque materials of other colors, etc.) and/orother layers (e.g., metal, dielectric, semiconductor, etc.). Opaquemasking materials such as these may also be formed on an inner surfaceof a planar rear housing wall formed from glass, ceramic, polymer,crystalline transparent materials such as sapphire, or other transparentmaterial.

Optical components 18 may be mounted under one or more windows such asoptical component window 30 of FIG. 3. Optical components 18 underwindow 30 may include a visible image sensor, an infrared image sensor,an optical proximity sensor, an ambient light sensor, and one or morevisible and/or infrared light-emitting diodes and/or visible and/orinfrared laser diodes. Light sources such as light-emitting diodesand/or lasers (e.g., vertical cavity surface emitting lasers and/orother lasers) in components 18 may produce image sensor illuminationsuch as visible camera flash illumination and/or infrared sensorillumination and/or may produce status indicator illumination.

In an arrangement of the type shown in FIG. 3, one or more openings forone or more respective optical component windows such as opticalcomponent window 30 may be formed in the opaque masking layer ofinactive area IA. In some configurations, optical component windows 30are free of coating layers. In other configurations, a partiallytransparent layer (e.g., a layer of polymer containing dye and/orpigment such as a layer of black ink) or other structures may overlapthe openings to adjust the appearance of the optical component windows(e.g., to adjust the appearance of the optical component windows so thatthe optical component windows have appearances that match thesurrounding opaque masking layer). Electrically adjustable shutters maybe incorporated into windows 30. This allows windows 30 to be matched inappearance with surrounding housing structures or to have other desiredappearances when it is not necessary to allow light to pass throughwindow 30 and allows windows 30 to be rendered transparent during use ofoptical component 18 or other structures overlapped by windows 30.

Optical component windows may, in general, include any suitable layer(s)of material (e.g., inorganic and/or organic thin-film layers, partiallytransparent metal films, dielectric coating layers such as thin-filminterference filter coatings formed from stacks of dielectric layers,etc.). These layers of material may be formed within an opening in alayer of opaque masking material (e.g., on the underside of a displaycover layer or housing layer) and/or may be formed on the surface of oneor more separate transparent window members for windows 30.

In the example of FIG. 3, optical component window 30 is formed ininactive area IA of display 14 (e.g., an inactive border area in adisplay cover layer). If desired, optical component windows such aswindow 30 may be formed in other portions of device 10 such as portionsof a rear housing wall formed from a transparent member coated withopaque masking material.

FIG. 4 is a rear perspective view of an illustrative electronic devicesuch as device 10 of FIG. 3. As shown in FIG. 4, an optical componentwindow such as window 30 may, if desired, be formed from a transparentmember mounted in an opening in a rear housing wall formed on rear faceR of housing 22. Window 30 may, for example, include a transparentmember in a raised window mount (e.g., a support structure such as bezel32) or other inset region within the rear housing wall. In this type ofconfiguration, the transparent material forming window 30 may be thesame as the material forming the rear wall of housing 22 and/or mayinclude different materials (e.g., transparent plastic, clear glass,transparent crystalline material such as sapphire, transparent ceramic,etc.). Window 30 may overlap a light source (e.g., a visiblelight-emitting diode or laser that serves as a camera flash) and avisible light digital image sensor (e.g., a visible light camera) and/orother optical components 18.

Electrically adjustable shutter 8 may overlap optical components 18and/or other structures within the interior of device 10, as illustratedby the overlap of shutter 8 and component 40 of FIG. 5. Window 30 inFIG. 5 may have transparent layer 42 (e.g., a portion of a display coverlayer overlapping display 14 of FIG. 3, a rear housing wall in housing22 on rear face R of device 10, a transparent window member surroundedby a support structure such as structure 32 of FIG. 4, and/or othertransparent window member. Optional coating layer 44 (e.g., a partiallytransparent ink layer, a clear antireflection layer, an ultravioletlight blocking layer, an infrared-light-blocking layer, and/or otherlayer(s) may be formed in window 30 (e.g., on the underside of layer 42,etc.). Component 40 may include one or more of optical components 18 orother component or structures to be selectively hidden under shutter 8.These components and structures may include, for example, agency textand other text (logos, manufacturing country of origin, regulatorycompliance notices, model numbers, serial numbers, etc.), may includewater dots and other moisture exposure indicator structures, may includeinternal components for which viewing is sometimes desired (e.g.,internal components such as integrated circuits, printed circuits,sensors, or other circuitry for which viewing may be desired forinspection or repair), may include a display such as display 14 (e.g.,an array of pixels 28 in a transparent display or other display), or mayinclude other components or structures.

When it is desired to hide component 40 from view by a user such as user46 who is viewing device 10 in direction 48 from the exterior of device10, shutter 8 may be placed in a non-transparent state (e.g., an opaquestate, a state with high haze, etc.). When it is desired to allow lightto pass through shutter 8, shutter 8 may be placed in a different statesuch as a high transparency (clear) state. Shutter 8 may also beadjusted to serve as an optical filter (e.g., an adjustable spectralfilter that exhibits one or more desired visible light and/or infraredlight absorption spectra so that shutter 8 serves as a color filter, aninfrared light-blocking filter, and/or other optical filters) or toserve as a reflective element (e.g., a full or partial mirror). Ifdesired, shutter 8 may overlap a component (e.g., a light-emitting diodeor laser that serves as a camera flash) without overlapping an adjacentcomponent under window 30 (e.g., an adjacent visible light digital imagesensor). Configurations in which shutter 8 overlaps multiple opticalcomponents 18 under a common window 30 or other portion of device 10 mayalso be used.

FIG. 6 shows how display 14 may be transparent and may be interposedbetween viewer 46 and shutter 8 (e.g., so that array of pixels 28 fordisplay 14 is interposed between the display cover layer for display 14such as layer 42 and shutter 8). In this type of configuration, opticalwindows may be formed on both the front F and rear R of device 10. Whenuser 46 desires to view object 50 through display 14 and shutter 8(e.g., in a mixed reality application in which display 14 is displayingcontent that is overlaid on real-world objects), shutter 8 may be placedin a transparent state. When user desires to view images on display 14without viewing object 50, shutter 8 may be placed in an opaque state.Shutters such as shutter 8 of FIGS. 5 and 6 may also be configured tooverlap the front of all or part of display 14 (e.g., so that shutter 8is interposed between display 14 and user 46 and so that shutter 8 isinterposed between the display cover layer for display 14 and the pixelarray for display 14 as shown by shutter 8 and illustrative component 40of FIG. 5).

In the example of FIG. 7, component 40 is an optical component such as alight source (e.g., a packaged light-emitting diode or laser). Light 56is emitted by a light-emitting diode die and/or laser die such as die 52and is collimated by curved reflector 54.

FIG. 8 shows how component 40 may be a packaged light-emitting diodeand/or laser having a Fresnel lens structure 58 that collimates light 56that is emitted by die 52. Structures such as the light sourcestructures of FIGS. 7 and 8 may be used for illuminating images forvisible and infrared image sensors, may be used as a flashlight, may beused to generate visible alerts (e.g., by flashing to serve as anotification of an incoming message, etc.).

FIG. 9 is a cross-sectional side view of an illustrative electricallyadjustable shutter formed from a smectic A (SmA) liquid crystal device.Smectic liquid crystal devices may be characterized by bistableoperation, low power consumption, and low off-axis light absorption whentransparent. In this type of arrangement, shutter 8 has an upper layersuch as ultraviolet light blocking layer 60 (e.g., an ultravioletfilter). Layer 60 may prevent ultraviolet ambient light from damagingmaterials in shutter 8. Upper electrode 64 may be formed on uppersubstrate 62 facing liquid crystal layer 66. Lower electrode 68 may beformed on lower substrate 70 facing liquid crystal layer 66. Upper andlower substrates 62 and 70 may be formed from clear materials such aslayers of transparent glass or plastic. Upper electrode 64 and lowerelectrode 68 may be formed from transparent conductive material such asindium tin oxide or other transparent conductive material. Electrodes 64and 68 may be used to adjust the electric fields applied to liquidcrystal layer 66 during operation of electrically adjustable shutter 8to adjust the appearance of layer 66. Layer 66 may include a mixture ofliquid crystal material, ionic dopants, and dye. The dye in layer 66 maybe selected so that shutter 8 varies in appearance between black andclear or between other colors, other amounts of light absorption, lighttransmission, light reflection, and/or color appearance.

When not being actively switched between different optical states (e.g.,different amounts of light transmission), smectic liquid crystal shutter8 does not consume power. When it is desired to change from a firststate (e.g., a dark and hazy state) to a second state (e.g., a clearstate with a haze of less than 5% or other suitable low-haze value), abrief (e.g., less than a fraction of a second) alternating currentsignal of greater than about 1 kHz in frequency and a voltage of about+/−100 V or less may be applied to layer 66 with electrodes 64 and 68.When it is desired to revert to the first state from the second state, abrief low-frequency signal (e.g., about 60 Hz) may be applied acrosselectrodes 64 and 68.

FIGS. 10 and 11 are cross-sectional side views of electricallyadjustable shutter 8 in an illustrative configuration in which shutter 8has been formed from an electrowetting device (e.g., anelectrowetting-on-dielectric device). As shown in FIG. 10, shutter 8 mayhave transparent upper substrate 86 and transparent lower substrate 74.Immiscible liquids such as water 84 and oil 82 may be interposed betweensubstrates 86 and 74. On lower substrate 74, outer electrodes 76 andinner electrode 78 are laterally separated by gaps and are thereforeelectrically isolated from each other. Electrodes 76 and 78 (or, in theillustrative embodiment of FIGS. 10 and 11, at least central electrode78) may be formed from transparent conductive material such as indiumtin oxide or other transparent conductive material. Hydrophobic coatinglayer 80 is formed over electrodes 76 and 78. Oil 82 (e.g., dark oil)contains dye or other colorant (e.g., to render oil 82 black, otheropaque colors, a non-neutral color, or other desired color). When novoltage is present across electrodes 76 and 78, oil 80 spreads acrosslayer 80 and prevents light from passing through central region 90 andperipheral region 92 of shutter 8. When a voltage is applied acrosselectrodes 76 and 78, oil 80 is drawn on top of outer electrode(s) 76.This leaves central region 90 free of oil and renders region 90transparent (e.g., shutter 8 is in its transparent state), as shown inFIG. 11. A top view of shutter 8 of FIGS. 10 and 11 is shown in FIG. 12(e.g., in a configuration in which shutter 8 is configured to fit oversome or all of an elongated window structure such as window 30 of FIG. 4or other optical window 30 in device 10).

If desired, other types of electrically adjustable optical shutterdevice may be used to form shutter 8. For example, guest-host liquidcrystal devices may be used in which guest anisotropic dyes of desiredcolors are incorporated into host liquid crystal material between a pairof transparent electrodes. Another illustrative adjustable device thatmay be used in forming adjustable shutter 8 is a polymer stabilizedcholesteric liquid crystal device, which is hazy when off and clear whenon. Polymer dispersed liquid crystal devices, electrophoretic liquidcrystal devices, transreflective liquid crystal devices (e.g., devicesbased on cholesteric liquid crystals), liquid crystal devices withpolarizers, electrophoretic devices, microelectromechanical systemsdevices (devices with microlouvers), electrochromic devices, and/orother devices with adjustable optical properties may be used in formingshutter 8, if desired. The configurations of FIGS. 9, 10, 11, and 12 aremerely illustrative.

During operation of device 10, control circuitry 16 may place shutter 8in an opaque (e.g., non-transparent) state whenever shutter 8 does notneed to be transparent to support operation of underlying component 40of FIG. 5. When component 40 desires to receive or transmit light,control circuitry 16 may adjust shutter 8 to increase the transparencyof shutter 8 (e.g., to place shutter 8 in a transparent state). Aftercomponent 40 has been used, the transparency of shutter 8 may again bereduced so that shutter 8 can block component 40 from view.

In some situations, shutter 8 may exhibit three or more different states(or continuously adjustable behavior). For example, shutter 8 may beplaced in a dark state, a clear state, or a reflective state. Thereflective state may be used, for example, when it is desired to adjustthe cosmetic appearance of device 10 or when it is otherwise desired torender the appearance of component 40 reflective (e.g., when it isdesired to use the surface of shutter 8 as a mirror to reflect a user'sface or other image). Non-transparent states for shutter 8 may be usedto help blend or harmonize the appearance of component 40 and/or window30 with surrounding portions of device 10.

If desired, shutter 8 may be adjusted to form a variable neutral densityfilter for a visible image sensor and/or an infrared image sensor or maybe adjusted to change the transmission spectrum of shutter 8 and allowshutter 8 to serve as an adjustable spectral filter for component 40. Insome situations, a light-emitting diode or laser (e.g., a camera flashdiode or laser) may be flashed to create a visible notification for auser (e.g., that an alarm has expired, a message has been received,etc.). If it is desired to dim this flashing behavior, a shutter 8 thatoverlaps the light-emitting diode or laser may be placed in a partiallytransparent state.

In some arrangements, shutter 8 may be placed in a transparent state toallow the interior of device 10 (e.g., interior components in aninterior region of housing 22 such as integrated circuits, printedcircuits, etc.) to be viewed (e.g., for games, educational purposes,failure analysis, or cosmetic considerations). Display 14 may betransparent in some arrangements (e.g., a transparent organiclight-emitting diode display, etc.) as described in connection with FIG.6. Shutter 8 may be used to create a variable opacity backing layer fora transparent display and/or can be used to create a cosmetic cover thatoverlaps the outer surface of display 14.

Optical data ports (e.g., ports having light-emitting diodes, lasers, orother optical transmitters and having photodetectors to receive data)may have optical windows such as window 30 and these ports may be hiddenwith shutters 8 when not in use. Shutters such as shutter 8 may alsocontain conductive material (e.g., carbon particles or other conductivematerial in oil 82) and may be used in forming an antenna (e.g. anantenna for communications circuitry 20). By varying the shape of oil 82while adjusting shutter 8, the electromagnetic properties of the antennacan be adjusted (e.g., to tune the antenna to cover desired frequencybands, etc.). Movable electromagnetic interference (EMI) shields mayalso be created in this way. When shielding is desired, conductive oilin an electrowetting shutter device can be moved into a position inwhich the conductive oil forms an EMI shield over a sensitive component.When shielding is not needed and/or it is desired to change theappearance of a portion of device 10, the electrowetting shutter devicecan move the conductive oil to a different location.

To determine whether device 10 has been exposed to environmentalcontaminants such as moisture, device 10 may be provide with moistureindicators (sometimes referred to as liquid contact indicators).Moisture indicators may be formed from water dot material (e.g., paperinfused with dye) or other material that changes appearance (e.g., fromwhite to red, etc.) when exposed to moisture. The moisture indicator maynot have an attractive appearance and can therefore be covered with anopaque shutter 8 when not being inspected. When a technician desires toinspect the state of the moisture indicator, shutter 8 may be placed ina transparent state (e.g., so that the moisture indicator that isoverlapped by the shutter can be viewed through the shutter). Ifdesired, an electrical moisture detector can detect when moisture ispresent and, based on this determination, control circuitry 16 canadjust the state of an electrically adjustable shutter (e.g., shutter 8may serve as a liquid contact indicator).

As described in connection with FIG. 5, component 40 may includeunsightly text (country of manufacture, model number information,government agency identification number information, etc.). Thisinformation can be hidden from view by shutter 8 during normal operationand revealed on selected occasions.

Components such as light-emitting diodes and/or lasers (see, e.g., lightsource components 40 of FIGS. 7 and 8) can sometimes be unsightly, sothe ability to cosmetically cover these light sources with shutter 8when not in use may allow components with an unattractive outwardappearance but enhanced performance to be used in device 10. Uncoveredcameras may give rise to privacy concerns. These concerns can beaddressed by placing shutter 8 over a camera (e.g., a visible imagesensor) in device 10. This allows the shutter to be closed duringoperation of device 10 except when the camera is in active use. Ifdesired, shutter 8 may serve as an adjustable neutral density filter oradjustable aperture. In an adjustable aperture arrangement, shutter 8may have an electrode pattern (e.g., a ring shaped pattern) that allowsdark oil 82 or other dark substances to create a circular transparentaperture or other transparent aperture of a desired adjustable diameter.Adjustable apertures may also be created by using ring-shaped electrodesin liquid crystal shutters or other shutters.

The foregoing is merely illustrative and various modifications can bemade to the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. An electronic device having opposing front andrear faces, the electronic device comprising: a display forming thefront face; a housing having a rear housing wall forming the rear face;an electrochromic component coupled to the rear housing wall; andcontrol circuitry configured to adjust the electrochromic componentbetween a first mode and a second mode.
 2. The electronic device definedin claim 1 wherein the control circuitry is configured to adjust theelectrochromic component between a first color in the first mode and asecond color that is different from the first color in the second mode.3. The electronic device defined in claim 2 wherein the first color isblue.
 4. The electronic device defined in claim 3 wherein the secondcolor is gray.
 5. The electronic device defined in claim 2 wherein thefirst color is selected from the group of colors consisting of: blue,red, green, blue-black, white, black, and gray.
 6. The electronic devicedefined in claim 1 wherein the control circuitry is configured to adjustthe electrochromic component between exhibiting a first haze in thefirst mode and a second haze that is different from the first haze inthe second mode.
 7. The electronic device defined in claim 1 wherein theelectrochromic component comprises first and second electrodes andwherein the control circuitry is configured to adjust the electrochromiccomponent between the first and second modes by applying a voltage tothe first and second electrodes.
 8. The electronic device defined inclaim 7 wherein the first and second electrodes are respectively formedon first and second glass substrates.
 9. The electronic device definedin claim 1 wherein the electrochromic component is adjustable between atleast one additional mode.
 10. The electronic device defined in claim 1wherein the electrochromic component is configured not to draw powerwhen in the first mode or the second mode.
 11. The electronic devicedefined in claim 10 wherein the electrochromic component is continuouslyadjustable between the first mode and the second mode.
 12. Theelectronic device defined in claim 1 wherein the rear housing wall isformed from a planar glass member.
 13. The electronic device defined inclaim 12 further comprising: a camera that receives light through therear housing wall.
 14. An electronic device having a front and a rear,the electronic device comprising: a display facing the front; atransparent member at the rear; an electrochromic component positionedbehind the transparent member; and control circuitry that is configuredto adjust the electrochromic component between exhibiting a first colorand a second color that is different from the first color.
 15. Theelectronic device defined in claim 14 wherein the first color is aneutral color and the second color is a non-neutral color.
 16. Theelectronic device defined in claim 15 wherein the first color is grayand the second color is blue.
 17. The electronic device defined in claim16 wherein the electrochromic component comprises first and secondelectrodes and wherein the control circuitry is configured to apply avoltage to the first and second electrodes to adjust the color of theelectrochromic component.
 18. The electronic device defined in claim 17wherein the transparent member is a rear housing wall.
 19. An electronicdevice having first and second sides, the electronic device comprising:a display facing the first side; and an electrochromic component visibleat the second side and adjustable between exhibiting a first color and asecond color that is different from the first color.
 20. The electronicdevice defined in claim 19 further comprising: a housing, wherein theelectrochromic component is configured to be adjusted based on a user'sinteraction with the housing.